Aromatic diamines which contain at least one alkyl substituent in the ortho position to a first amino group and two alkyl substituents in the ortho position to a second group are known in the art and are described as being useful in the preparation of moldings based on polyurethane and/or polyurea chemistry. See, for example, U.S. Pat. Nos. 4,218,543, 4,269,945, 4,288,564, 4,296,212, 4,298,701, 4,379,105, 4,442,235, 4,495,081, 4,595,705, 4,595,742, and 4,607,090, and British Patent No. 1,534,258. In fact, one of these types of amines has met with substantial commercial use in the production of molded parts via the RIM process. Specifically, diethyltoluene diamine (DETDA) is currently being used on a large commercial scale as a chain extender for the production of polyurethane and polyurea moldings via the RIM process. Formulations based on DETDA allow for fast demold times and high productivity because of the high reactivity of DETDA. In fact, the concentration of DETDA which can be used is generally limited due to the high reactivity. Typical concentrations are in the range of from about 23 to about 25 per cent (based on the weight of all the active hydrogen containing components).
Reaction products of ethylenically unsaturated dicarboxylic acid anhydrides (e.g., maleic anhydride) and aromatic diamines are known. Thus the reaction product of one mole of such an acid with from 2 to 20 moles of diamine have been described as being useful in the preparation of epoxy based thermosetting resins (see Japanese Published Application Nos. 57016023 and 56166225).